X-ray phantoms are known calibration devices and teaching aids for conventional x-ray machines. Prior art phantoms are available in a number of variations, some being plastic replicas of the human body or specific portions thereof, while others consist of actual human bones cast in plastic. These phantoms are used to train x-ray technicians in the proper positioning of the human body for the various x-ray images that are taken for diagnosis, and the resulting films may be studied to aid in calibrating an x-ray machine for identifying the radiographic image of known structures.
Extensive scientific work has been done in measuring x-ray dose and image quality of x-ray imaging equipment. Test phantoms and measurements have evolved to facilitate evaluation of an x-ray imaging machine. From a regulatory point of view, radiation dose is often the key parameter of concern. Today, the general policy is to protect patients from unreasonable radiation dose, while still allowing the radiologist to obtain an image of acceptable quality. Some imaging facilities have adopted their own rigorous quality assurance programs, while others have not.
In recent years, there has been increased interest in independent, third party monitoring of image quality along with radiation dose. A variety of phantoms and dosimeters have been used for this type of application. Image quality can often be increased by utilizing protocols resulting in excessive radiation dose levels, while dose measurements can be minimized by selecting protocols which provide inadequate x-ray images. For this reason, accurate testing has traditionally required an on-site visit by an independent technician or scientist who is able to verify that the same protocols are followed for both the image quality and radiation dose measurements.
A significant disadvantage of this monitoring approach is the cost associated with having an independent technician or scientist accompany the phantom to oversee the imaging thereof. With ever increasing concern for the quality of care, there is increased interest in regulatory evaluation of x-ray equipment. However, this runs counter to the pressure on governmental agencies to reduce costs. Thus, a genuine need exists in the art for facilitating gathering of reliable, non-falsifiable radiation dose and image quality information by an independent agency without the presence of their own independent technician or scientist on-site to oversee performance of the measurements.